Callous-unemotional (CU) traits predict behavioral problems in adolescence. But little is known about early modulatory factors. Behavioral Inhibition (BI) in particular has been suggested to protect against the development of CU-traits. This temperamental predisposition is characterized by heightened environmental sensitivity. The current prospective longitudinal study examined whether BI at 15 months of age predicted lower CU-traits across development to age 21. A longitudinal sample of normatively developing children (n = 125) was used. BI was assessed at 15 months using a standard stranger/robot paradigm. CU-traits were assessed at 2, 5, 9, 12, 14, 17, and 21 years with parent, teacher, and self-reports. Developmental pathways across all available data points were examined using Bayesian mixed models and k-means cluster analysis. Infant BI predicted lower CU-traits across development for girls, suggesting that BI buffers the long-term development of CU-traits for girls. CU-traits peaked in early adulthood. Boys scored higher and showed higher increases in CU-traits than girls from childhood onward. There was no gender difference regarding infant BI. Together, the findings demonstrated gender differences in the development of CU-traits, with a protective role of BI for girls. These results shed new light on the developmental trajectories and protective factors of CU-traits and provide starting points for interventions aiming at increasing children’s responsiveness to external cues to prevent antisocial traits and conduct problems.

冷酷无情（CU）特征预测青春期的行为问题。但对早期调节因素知之甚少。特别是行为抑制 (BI) 已被建议用于防止 CU 性状的发展。这种气质倾向的特点是对环境的高度敏感。目前的前瞻性纵向研究检查了 15 个月大时的 BI 是否预测到 21 岁整个发育过程中的 CU 特征较低。正常发育儿童的纵向样本 ( n= 125) 被使用。BI 在 15 个月时使用标准的陌生人/机器人范例进行评估。CU 特质在 2、5、9、12、14、17 和 21 岁时通过父母、老师和自我报告进行评估。使用贝叶斯混合模型和 k-means 聚类分析检查了所有可用数据点的发育途径。婴儿 BI 预测女孩在整个发育过程中的 CU 特征较低，这表明 BI 缓冲了女孩 CU 特征的长期发展。CU-特质在成年早期达到顶峰。从童年开始，男孩的得分更高，CU 特质的增加也高于女孩。婴儿 BI 没有性别差异。总之，研究结果证明了 CU 特征发展中的性别差异，BI 对女孩具有保护作用。